Protective device.



E. R. CARICHOFF.

I PROTECTIVE DEVICE. APPLICATION HLED JAN-15. 1914.

1,142,552 Patented June 8, 1915.

INyENTUH .EUE'EJVEI H C IDHUFI',

v I .His d'rranzsrzy- UNITED STATES PATENT OFFICE.

EUGENE in. sameness,- or scnnnncmny, New YORK, ASSIGNOR 'ro GIlNEBAL ELECTRIC COMPANY, a CORPORATION OF NEW YORK.

IROTECTIVE DEVICE.

Specification of Letters Patent.

Patented June 8, 1915.

Application filed January 15, 1914. SeriaiNo. 812,194. r

' To all whomit may concern:

Be it known that I, EUGENE R. OARIOHOFF, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in- Protective De vices, off which the following is a specification.

for electric circuits, and has for its object the provision of means whereby the application of a higher voltage to the circuit than "was intended to he applied, due t-ooarelessnessor other c'auses, is prevented.

My invention relates more specifically to a protective device connection with electric railway ystenis designed to operate on different potentials.

Electric railways are common at the presout time in which the cars operate at difierent voltages, say, for instance, at 1200 and 600 volts at different times. In such railway systems it is customary to provide each car with a small generator or dynamotor which when the car is upon a 1200 volt secw tion of line serves to reduce the high voltage of the line to a lower voltage, say 600 volts, for the purpose of supplyingthe controlling and the lighting circuits of the car.

When the car is operating upon a 600 volt section of line the control and lighting circuits are disconnected from the dynamotor and connected directly to the trolley circuit. In an equipment of this kind it is desirable that means he provided for preventing the connecting of the control and lighting circuits to thetrolley directly when the latteri'isoperating at high voltage; that is, it is desirable to make it absolutely impossible for the high voltage ever to be ap- One of the objects of my invention is to providea simple andeii'ective device of this general character which will prevent the occurrence of accidents of the character above described on electric railway lines and in other connections.

In the accompanyingdrawing .in which I have illustrated my invention embodied in concrete form, Figure 1 is a diagrammatic illustration of one form of my invention; and Fig. 2 is a diagram representing a modific'ation thereof.

Referring to the drawings, M and M represent two motors on the car and G-C My invention relates to protective devices are the master controllers which operate the control circuits. The main controller located 1n the rboxl) is of the standard and well known form used'in equipments of this character and requires no further description. The trolley T has a direct connection with the main controller through the wire 1-0 and current is supplied to the control circuit through the wire 11. This control circult is supplied from the motor generator or dyna-motor 12 through the wire 13, or is supplied direct from the trolley through the wire 14:, depending upon the trolley potential. A switch 15is provided for changing the connections of the control circuit from the dynamotor to the trolley.

One of the objects of'my invention isto prevent the high voltage from being applied to the control circuit in case the, op-

valu-es. In the form of my invention shown in F ig. 1, the switch 16 only responds to a high current value, corresponding to a high potential on the trolley, and does not respond to a low current value. On the other hand, the switch 17 responds to a low current value corresponding to a low potential on the trolley. Switch 17 will also, of course, respond to a high current value. Switch 16 is provided with contacts18 which when closed by the actuation of the switch, short circuit the winding of the switch 17. The switch 17 when it operates connects the trolley circuit to either the trolley or the dynamotor, depending upon the position of the switch 15. In order to prevent the closure of the switch 17 before the switch 16 gets a chance to short circuit the Winding of switch 17 I provide, in the form shown in Fig. 1, a dashpot 19 for delaying the action of the switch 17.

As thus constructed and arranged the operation of the form of device shown in Fig. 1 is as follows: Assuming that the switch 20 is closed and the switch 15 in the position shown in the drawing, connections are made for operation on high voltage. connection from the trolley is through the switch 20, wire 14, through the contacts on the switch 15 through the dynamotor to The.

' has the open wh n he ground are is co clrccii; from ihe ijEfQi ley direct to the cohtioi c1. he cow trol circuit, hoe" *er made cugh the Wire 13 iiehen from the djy'nnmotor through the ocac'i s on c switch 15 h ough the .YiLU of 5; echo J5 and J series to ground. 'li'zc d numotor i3 U, say for in Under thcee 00nd ions the switch The switch 1'43 how 155 operate action which d 21 she oh 11 the i new the hzciiey z-si'zouid he tho" 3 (ii) dirccn with the co '1" etc 21 H v seems that i "will he coon ed dicect $0 the W s the SWlLCi'lQS i6 and 17. out with I n rangement shown this voice t Oi 1200 cannot be :mphed to the control ciruit. As soon hih potentiei is applied 0 the smtch 16 chic hatter cperzf s and.

voimg'e applied so ic, and. it having hort cicc'uits the "\x'indin 0' the s .5011 1?, Q1: course, the "Winding oi:

d ncrgiricd in passing fi'oin low to so @011 1'? has zdec m'iei'zi'te and ciese the ,i ta '1 cm; sum not in the c1051 ing is shot on .ec switch 16 ore it fully vios close 1'01 1 e control to the ceased t1 switch 1 q n L shone e1 rig. i. cit cw invention ion shcwn in. the drawingthe dynm 1&3 connected in circuit and the conhf-ze" mm the Wire 13 and contacts of the switch 15, thence h the windings of the switches 16, 11 1,3 in so ground. Since the dynatcr gives the proper voltage under this :cndition the switch will operate upon Lois 1' ow current and close a connection from the dynamotcr the controi circuit as before. Likewise, when the switch 15 is chrowh' to the opposite position and the Yehazagge of the trolley is low, the switch 15 being; 'ihi'owh to the proper position the switch wili operate to coimecxi the trolley direct t0 the control circuit 15 however the't 'ciiey should he on the 600 vch: cizcuiir, with the contacts 2-2 of the ewliich 3.5 in cnggegemei'ie with the se ments and the icy ehouid run on =30 120C voh. secticn, we? neglecting to throw the switch 7 ch 28 would not operate but will the open. position due to the high "he switch 16 Wiih however, close i circuit the Wiliilig of the switch nth! these circui'nsimices, 1n order Z0 en; p potential tothe confiroi circuit 1t wllibe ne essary to 'ti'l'row the switch 15 0 its proper positio; WhEIfQl'l'p-fii'l the switch 23 W111 clcse 4M, 6111*"; T 1 '1 q n p w Mimic the om -e1 connccuoi. e ar cement of F 2 8.0001 phshes the same result that shown in Fig, 1, the difference 1 the apparatus being that instead of using switch with a dc ed action, as shown in i, a close switch is used which will no; all on a. high curren'tu 11 whereby it is impossible. for a higher voltageie be MDDiiQd to a centre circuit than was intended, this being accomplished by very simole and inexpensive apparatus.

u Wiii be seen that I have prcvided means Whiie 1 have described my invention as embodied in concie te form and as operating in e specific manner in accordance with the nsiteili isl'etmea it should he undersiood that i do iihtlimit; my invention thereto, since various modificaiions thereof will suggest them ves to those skilled the art Withcut @G,)j"ihi2fl from). the spirit of my inven tion, the scope of which is set ifci'th in the annexed claims What- 1 claim as new and desire to secure by Letters Frien't of the United Staaes is;

1, A giviotec'aia 'e device for eiectric circuii's o emting on a phnuiity of voltages sing two switches having their Windin one of which responds fice, entvehie than the other and; "hereby the sWiic-h which res'pends 10w curmm value than me Qihfil, switch which responds ta the higher aux-ram short dram the Wir g 0f tha swibfi'ia Wham apez'umd.

comprigm ings in Sw ss lower 01 swiich 116$ having their win we of Whmh rewsn is to value opzyiat a Md means whereby the sio um 0i: swatch z'espondmg t0 the.

CLEifZfii'iii gavevented m hlgh mix) sei;

CAQEJ QJHOFF.

m is. 5110213 @ircnitad; l P 1 v 

